Fusing link



Sept. 19, 1950 w. F. KRAMER FUSING LINK Filed Sept. 9, 1946 ATR/VEYPatented Sept. 129, 1950 FUSING LINK Walter F. Kramer, Detroit, Mich.

Original application January 21, 1946, Serial No.

642,540. Divided and this application September 9, 1946, Serial No.695,784

8 Claims.

This invention relates generally to fusing links I 'and refers moreparticularly to improvements in fusing links of the type usedy intheautomatic operation of fire extinguishers. This application is adivision of my copending application Serial `No. 642,540 filed January21, 1946, now Patent No. 2,480,033, issued August 23, 1949.

Automatic rlre control apparatus such as fire extinguishersare usuallyequippedwitha fusing linkfor some equivalent element designed toautomaticallyrelease a fire extinguishing fluid in gas or fluid form inresponse to apredetermined increase in the temperature of the atmosphere`ambient to the apparatus.` Thus, the effectiveness ofthe apparatus toextinguish or control fires depends to a great extent on the ability ofthe fusing link or similar device to initiate operation of the apparatuswith a minimum delayrafter a lire is started.

With the above in view the present invention has as one` of itsprincipal objects to vprovide a fusing link which is highly sensitive topreselected abnormal temperaturesand assures instantaneous operation ofthe apparatusfto discharge fire extinguishing fluid when the atmosphereambient to the fusing link reaches the preselected temperature..

Another object of this `invention is tov provide t a fusing linkcomposed of a relatively. 'few-simfire extinguisher shown in Figure 1;

Figure 3 is a cross sectional View taken onV the planeindicated by theline 3-3 of Figure 1; and Figure 4 is a detail elevational view of apart of the fusing link shown inFigure 3 and illus- `trating one methodof rmaking the fusing link.

- For the purpose of illustrating this invention, I have selected a fireextinguisher of the type shown in my copending application, Serial No.642,540 filed January 21, 1946, althoughlit will be understood as thisdescription proceeds that the fusing link featuredherein may beadvantageously employed to initiate -the operation of other types ofautomatically operable fire control equipment Briefly the fireextinguisher disclosed herein is adapted to besupported on the ceilingused and especially satisfactory results have been l reference numeralI0.

of a room or other enclosure and is automatically operated by myimproved fusing link in response to a predetermined temperature rise todischarge the contents of the extinguisher into the enclosure in theform of an enveloping fog. The fog is discharged under pressurey so thatitrapidly displaces the oxygen around the lire and smothers the latter.

The fusing link is shown best in Figure 3 of.

the drawings and is indicated generally by the As shown in Figure 3 ofthe drawings the fusing link I0 comprises a ring II preferably formed ofa non-metallic material such, for example, as fiber, rubber, syntheticrubber or some equivalent material and composed of two or more segmentsI2. normally confined in a sectional band I3 and are urged outwardly bya segmental leaf spring I4 positioned in the ring II with the oppositeends respectively bearing on the inner surfaces of the ring segments.The sections of the band I3 are formed of a metal having a high thermalconductivity such, for example, as copper or similar metals, and areheld together by a fusing metal having a melting point'in a range of 140F. to 240 F., for example. Any fusing metal having a sufciently low-melting temperature may be obtained with vcompositions produced by theCerro Bend Manufacturing Company or by the Belmont Smelting and RefiningCompany. The construction is such that the various sections of the bandI3 are released from one another when the temperature ambient to thefusing link I0 approaches the melting point of the fusing metal employedto secure the sections together. When this condition exists, the leafspring I4r forces the segments I2 of the ring II Yand the sections ofthe band I3 apart with an explosive action. Disintegration of the fusinglink instantaneously releases the fire extinguishing uid in a manner tobe more fully hereinafter described.

Before discussing the means for releasing the re extinguishing fluid inresponse to disintegration of the fusing link, itis pointed out that theband I3 actually comprises eight sections indicated in the drawings by'the reference character I5 and arranged in pairs. The sections ofgeachpair are :formed lwith arcuate portions I6 and with radially outwardlyextending flanges I'I. The arcuate portions I6 of one section overlap Ithe arcuate portions of an adjacent section and are secured together bythe fusing metal to form the band I3. The flanges II on the sections areThe segments I2 arev registrationwith the opening |2. l i3 nallythreaded at the outer end for threadably positioned in contact with eachother and are arranged 90 apart as clearly shown in Figure 3 of thedrawings. In operation the flanges il form fins `which project asubstantial distance into the'atmosphere ambient to the fusing link andserve as heat conductors to facilitate the transfelI of heat to thefusing metal. In the interests of economy in manufacture,"each pair lofsections are formed of one piece of sheet metal in the manner clearlysholwn in Figure 4 of the drawings and the return bent portion I8 con'nectirig the extremities of the flanges are sheared off to separate thesections.

It has previously been stated that the fusing link I is applied to afire extinguisher of the type shown in my above Yidentiiied copendingapplication. This re extinguisher comprises a container I3' and adischarge nozzle The container is in the form of an elongated'tubesealed at opposite ends' and adapted to contain a liquid-having ireextinguishing characteristics such, for example, as Vcarbontetrychloride. The Vtub'e has an opening |2 intermediate the ends andafitting I3 in the form of a casing or forging -is brazed or otherwisesecured to the tube in The tting is formed with an annular flange i4interreceiving the noz'zle yThe nozzle |I comprises acap 26 threadably.Vengageable with the annular flange I4 on` the tting i3 and having acentral opening 2l re'gistering with an outwardly extending tubularextension 28 of the cap. The extension 28 has a reduced portion 2Q by anannularI partition 3| having orifices 32 therethrough.

A plunger33 is slidably supported in they guide l33 Vand is formed witha head 3' at the inner end positioned ,inl the annular flange M adjacent"l the outer ends of cartridges 24. The cartridges 2!l`contain asuitable gas, such for example, as

carbon dioxide under pressure, and are slidably supported vwithin thecontainer lil by guides 1| 62,# The guides |6 also provide supports forsuitable punches 2| positioned to respectively pierce the inner ends ofthe cartridges 2li upon inward vdisplacement of the latter relative tothe guides.

Theplunger 33 projects outwardly beyond thek head 35islslidablysupported on the outer end of the plunger. The spray head has asleeve portionY 33 slidably mounted on the plunger in concentricrelation to the reduced portion 23 and is fonmedlwith a frustro-conicalsurface 3? beyond the outer end of the reduced portion 29. The insidediameter of the reduced portion' 29 is somewhat greater th-'an theoutside diameter of the sleeve portion 3G onthe spray head and cooper,

ates with the sleeve portion to form -an annular A sealing gasket 40 isseated outer end of the reduced portion 29 and a spray 4 opening forabutting engagement with the head 34 on the plunger to seal the ports 32from the container and thereby prevent leakage of the contents of thecontainer.

The plunger 33 is normally urged to its innermost position shown inFigure 1 of the drawings by a coil spring 4| surrounding the plungerwith theainner end abutting-the head 345and with the 4words, the plunger33 is held in its outermost Cil ' reduced portion 2S at the outer endthereof andf-3 "is formed with a reduced tubular guide 3E) intermediateLthe ends. The guide 33 is concen- ,trically arranged with respect tothe extension l and the outerend of the guide is integrally connected tothe extension at the inner side ofV the@ the fusing link I0.

position shown in Figure 1 of the drawings by The fusing link I0 ispositioned with its ring |2 located between the head and an adjustablenut i6 having a left-hand threaded engagement with the sleeve portion 28The nut 46 is adjustably positioned on the sleeve portion 28 to locatethe plunger- 33 through the fusing element Yl) and spray head 35 in theposition shown in Figure 1 ofjthe drawings, wherein the head 34 isfirmly engaged with the gasket against the action of the coil springlll.

When the several parts of the re extinguisher are in the relativef'positions 'thereof shown in Figure 1 of the drawings,.the spring 4| isheld under compression` by the fusing-element l0 until the temperatureofthe'ambient atmosphere exceeds the fusing temperature of the metalpreviously described as securing the sections I5`of the lband I3together.V "When this takes place oneor more of the sections' I5 aredisconnected from the band and the spring lil displaces the ring-fromits position between the spray head 35 and the adjusting nut`46.This releases the spring Maand permits the latter to move the plunger 33inwardly at a rapid rate. Inasmuch as. the outer ends Vof the cartridges24 abut the head 34 on the plunger, it follows that the cartridges aremoved inwardly in their respective guides yby the plunger 33.

As the cartridges are forced inwardly by the spring 4|, the inner endsare .punctured-by the punches 22 and'gas under pressure Ais dischargedinto the container through openings 2|) in the tubular guides I6. Aspressure builds up in the container ID, the fire extinguishing uidtherein is discharged in the form of a spray through the noZZle'H. 1

What I Vclaimi'as my invention is:

l. A fusing link lcomprisingfa band composed of a plurality of arcuatesections connected together in overlapping relationship and separablefrom each other in the presence of heat, arcuate sections free fromconnection with each other and housed withink the band to provide aring, andspring means for forcing the ring sections laterally outwardlyagainst'adjacentportions of the band.

2. A fusing Alink comprising a plurality of arcuate sections connectedtogether to form a continuous band and separable from one another inresponse to'a predetermined rise in temperature of the ambientatmosphere, arcuate segments free from connection with each other andarranged in the band to form a ring, and spring means for urging thesegments outwardly against adjacent sides of the band with a forcesufficient form a continuous fband and connected together by a fusingmetal,l and spring means acting on fing on the inner surface of the bandfor forcibly displacing the sections laterally outwardly in response toseparation of the sections.

5. A fusing link comprising a plurality of arcu- Vate sectionscooperating with each other to form a continuous band and connectedtogether by a fusing metal, a fin projecting radially outwardly fromeach section of the band to facilitate the conduction of heat from theatmosphere to the fusing metal connecting the band sections, and springmeans within the band for forcibly displacing the sections laterallyoutwardly in response to fusing of said metal.

6. A fusing link comprising a plurality of arcuate sections arranged inoverlapping relationship to form a continuous band and connectedtogether with a fusing metal, arcuatersegments free from connection witheach other and arranged in the band to form a ring, and spring 'meanshoused within said ring and exerting an outward force on the ringsegments sufficient to forcibly displace the ring segments and bandsections `outwardly upon fusing of the metal holding two or more of thesections together.

'7. A fusing link comprising a [band composed of a plurality of arcuatesections connected together in overlapping relationship and separablefrom each other in the presence of heat above a predeterminedtemperature, a plurality of fins spaced from each othercircumferentially the band and extending generally radially outwardlyfrom the Iband to facilitate the conduction of heat from the atmosphereto said sections, arcuate segments free from connection with each otherand housed within the band to provide a ring, and spring means locatedwithin the ring for forcing the ring segments laterally outwardlyagainst the inner surface of the band.

8. A fusing link comprising a band composed of a plurality of arcuatesections having the free ends arranged in overlapping relationship andconnected together with a fusing metal, and spring means located withinthe band and acting on said sections to displace the latter laterallyoutwardly upon fusing of the metal holding the overlapping end portionsof the sections together.

WALTER F. KRAMER.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS Number Name Date r 1,623,887 Newton Apr. 5, 19271,953,582 Belknap Apr. 3, 1934 2,226,744 Roessner Dec. 31, 1940

